You know sunburns are your skin’s Enemy Number One. But did you also know that sun damage is the number one cancer-causer in the country? That’s why it’s oh-so important to practice sun safety. You can still enjoy your beach or pool time, just do it with a little more know-how. We break down facts from the American Academy of Dermatology and the Skin Cancer Foundation with the help of Dr. Elizabeth E. Richwine, a dermatologist with Marietta Dermatology and The Skin Cancer Center in Marietta, Ga.

6/12:The month and year that the U.S. Food and Drug Administration starts being stricter in regards to what sunscreen companies can claim on the labels. “Look for labels that state a sunscreen is able to help prevent both skin cancer and sunburn as this sunscreen will have passed more vigorous testing. Also, the words ‘sweat proof’ or ‘waterproof’ will no longer be seen on labels, as this is truly not possible. The term that will be allowed is ‘water resistant,’ and the label will state how long it lasts,” says Richwine.

1 in 5:The number of Americans who will develop some form of skin cancer during their lifetime.

1:The number of blistering sunburns in childhood it takes to double your risk of developing skin cancer later on in life.

3.5 million:The number of skin cancers diagnosed each year in more than 2 million people, making it the most common form of cancer in the U.S.

25-29:The age group in which melanoma is the most common form of cancer.

15 minutes:The time it takes for unprotected skin to be damaged by the sun.

10 am-4 pm:The time of day when the sun’s rays are strongest and when you should seek shade. Quick tip: Go into the shade if your shadow is shorter than you are, says Richwine.

30 minutes:How far in advance sunscreen should be applied before going outside.

1 ounce:The approximate amount of sunscreen (enough to fill a shot glass) needed to cover the exposed areas of the body.

30:The minimum SPF you should wear on your face and lips every day. “Sunscreens with an SPF of 30 keep out about 97 percent of the incoming UVB rays,” Richwine says. “Look for broad-spectrum protection, which guards against both UVA and UVB rays, as exposure to either ray can lead to skin cancer.”

2 hours:How often sunscreen should be reapplied.

70 – 80 percent:The percentage of the sun’s ultraviolet rays that travel through the clouds on overcast days.

3 inches:How wide your hat’s brim should be, according to The Skin Cancer Foundation, which encourages tightly woven hats to protect the head, neck, ears and tops of shoulders.

99 – 100 percent:The amount of UV radiation your sunglasses should protect your eyes from. “Make sure when you buy sunglasses that there’s a tag that states this percentage and choose a pair that covers the eyes, eyelids and nearby areas as much as possible,” Richwine says.

40 – 50+:The ultraviolet protection factor (UPF) of your clothes considered “excellent,” Richwine says. A UPF rating of 50 means the fabric of a garment will only let one-fiftieth (about 2 percent) of the sun’s UV rays reach the skin. A UPF of 15-25 is considered “good” and 25-29 is “very good.”

5:The UPF of your favorite white cotton T-shirt. This means 20 percent of the sun’s rays are reaching your skin. “Blue jeans, on the other hand, have a UPF of about 1700!” Richwine says.